Preparation of nitrogenous polysaccharide-supported ironporphyrins and their catalysis for the aerobic oxidation of cyclohexane

The coordinations of nitrogenous polysaccharide chitosan and chitin to chloro[tetraphenylporphinato]iron(III) have been investigated by means of the FTIR and UV-VIS analysis techniques, and the effect of their coordination on the aerobic oxidation of cyclohexane catalyzed by ironporphyrin has been studied. The new Fe-N coordination bonds between ironporphyrin and chitosan or chitin were found, and their coordination constants K, which were calculated by means of Langmuir's adsorption isotherm equation, were 9.68 x 10(-4) and 6.80 x 10(-4) L/mol, respectively, at equilibrium. It is shown that the coordination of the nitrogenous polysaccharide to ironporphyrin had an important influence on both the conversion and selectivity of the aerobic oxidation of cyclohexane catalyzed by ironporphyrin. The selectivity to the cyclohexanone and cyclohexanol production, the catalyst turnover, and the rate constants k of cyclohexane oxidation increased with increasing coordination constant K.